It’s not cheap unfortunately, £395, but I’m confident you’ll not find a better, more comprehensive kit around anywhere. (Sorry to be a bit smug, I’m proper pleased with this)

How does it work?

The air is drawn through the assembly by your trusty lungs, first through a 1 way valve, then the vaporiser. Then through the t-piece along the long tube and into the mask and your lungs, on the exhale your breath will be pushed back down the hose and into the rebreather bag, with excess air being pushed out through the chrome expiration valve on the mask. The again and again, each time adding some fresh air along with a little rebreathed air.